利用DisplayMetrics获取屏幕信息

public static String getDisplayMetrics(Context cx) { 
    	   String str = ""; 
    	   DisplayMetrics dm = new DisplayMetrics(); 
    	   //取得DisplayMetrics对象方法一
     	   //dm = cx.getApplicationContext().getResources().getDisplayMetrics(); 
    	   //取得DisplayMetrics对象方法二
    	   ((Activity)cx).getWindowManager().getDefaultDisplay().getMetrics(dm);
    	   int screenWidth = dm.widthPixels; 
    	   int screenHeight = dm.heightPixels; 
    	   float density = dm.density; 
    	   float xdpi = dm.xdpi; 
    	   float ydpi = dm.ydpi; 
    	  
    	   str += "The absolute width:" + String.valueOf(screenWidth) + "pixels\n"; 
    	   str += "The absolute heightin:" + String.valueOf(screenHeight) + "pixels\n"; 
    	   str += "The logical density of the display.:" + String.valueOf(density) 
    	   + "\n"; 
    	   str += "X dimension :" + String.valueOf(xdpi) + "pixels per inch\n"; 
    	   str += "Y dimension :" + String.valueOf(ydpi) + "pixels per inch\n"; 
    	  
    	   return str; 
    	}